eLua reference manual - MBED pio module

Overview

This module provide a function for accessing pin configuration features on the LPC17xx family of CPUs, and provides provides a pin mapping which corresponds to the pins and LEDs on the MBED platform. The pin configuration function allows the user to reconfigure pin function (as decribed in section 8.5 of the lpc17xx user manual, configure the pin as an open drain, and configure the pin as pullup, pulldown or tristate. Note that this module is a supplement of the platform independent pio module, not a replacement. Use this module only for setting up the MBED PIO pins, and the pio module for all the other PIO related operations. Below is a subset of available pin functions:

PWM

MBED Pin

ID

Function

LED1

1

FUNCTION_2

LED2

2

FUNCTION_2

LED3

3

FUNCTION_2

LED4

4

FUNCTION_2

p21

6

FUNCTION_1

p22

5

FUNCTION_1

p23

4

FUNCTION_1

p24

3

FUNCTION_1

p25

2

FUNCTION_1

p26

1

FUNCTION_1

UART

MBED Pin

ID

Function

p13

1 (TX)

FUNCTION_1

p14

1 (RX)

FUNCTION_1

p28

2 (TX)

FUNCTION_1

p27

2 (RX)

FUNCTION_1

In addition, this module provides pin mapping as found on the mbed board so that mbed.pio.p5 through mbed.pio.p30 map onto the mbed pins as described in the mbed handbook. LED pins are also usable, for example LED1 would correspond to mbed.pio.LED1.